▶ Play Episode
SHOW NOTES
The idea of growing harvestable fruit inside your home is tantalizing, but is it realistic? In this episode of Granite State Gardening, UNH Extension’s Emma Erler and Nate Bernitz share proven tips and solutions for growing fruits indoors — from the challenge of yielding fruit from plants indoors year-round to growing tropical fruits indoors and outdoors.
Featured question: using neem oil
Featured plant segment: blue passionflower
Closing gardening tip: what to do about broken limbs on trees and shrubs overwinter
Transcript
Transcribed by https://otter.ai
Nate B
Greetings, Granite State gardeners, it's hard to imagine anything more appealing than picking a piece of ripe fruit on your way to the kitchen without having to so much as get dressed or even go outside. That's the dream. But can it also be a real green thumb life? On today's episode, we separate legend from history and truth from fiction in our relentless mission to share nothing but proven tips and solutions for growing fruit inside your home. toil away with YouTube videos and influencer blogs no more. Save yourself from the agony of spending years coddling and singing to your indoor fruit tree in the desperate hope of getting one measly piece of fruit. After this episode, you will know what's possible and what's not, and how to make the possible your reality. I'm Nate Bernitz, joined by my co host, horticulturist and extension educator, Emma Erler, and this is Granite State Gardening from UNH extension.
So Emma, let's dig into it. What fruits can actually be grown indoors at least overwinter? And before you answer, I did some internet sleuthing on this topic. So maybe we'll fit a little mythbusting into this conversation. I found an article that was titled 12 fruit trees you can grow indoors for an edible yield. You know kind of spoiler It was not a reputable article, but it listed many fruits that you can grow indoors like not in a greenhouse but just inside your house and get bountiful fruit harvest so listed Meyer lemons, key limes, calamondin orange, tangerines, brown Turkey fig, passionfruit, peaches, nectarines, apricots, avocado, banana, mulberry and ground cherries. There are probably some other fruits that you know might make some different lists. But this is a pretty good place to start. You know, can you actually grow these fruits indoors?
Emma E
Oh, my what a place to start? Well, I think that list might be a little too good to be, might be a little too good to be true. I have certainly seen maybe all of those plants except for the mulberry grown successfully indoors. But by indoors, I mean a greenhouse and a heated one. So if that's what we're talking about, you know, growing inside of a heated greenhouse, we have those plants going year round. Definitely possible. But if you're talking about growing inside the average home, maybe not so much. The biggest shortfall is probably light, you know, really in order to get fruit plants to flower. And then of course to fruit you need to have highlight. And in most of our homes, we're not really going to be getting that. So unless you have a really bright sunny Southwest facing, you know, bay window, growing fruit trees indoors is going to be a bit of a challenge for you, or at least trying to grow them indoors year round for production.
Nate B
All right, I even read another article I mentioned before, there were some other fruits that could make some other lists. I found one that suggested you could even grow grapes indoors, they talked about training your grape vines up walls in your house, and just picking grapes right off your walls, which sounds pretty idyllic to be honest with you. But they also talked about growing Alpine strawberries in pots like on your window sills and how they would fruit continuously from early summer to mid fall again, that sounds incredible. Sign me up, or can I sign up?
Emma E
Again, I'm thinking it might be a little too good to be true. I again have seen grapes grown really successfully inside of greenhouses where they've been trellised they're getting plenty of light, there's some heat. Same with strawberries, but just trying to grow those on your window seller or you know better yet trying to grow grapes up, you're up a wall and dimly lit house, I just have a hard time believing that that's actually going to pan out for you. Really the outdoor environment is where these plants are going to be able to grow best.
Nate B
Yeah, I kind of had a feeling you would say that. And I do understand for multiple reasons why you would want to grow indoors and maybe you can with some of these. But I mean, when we're talking about outside, you have to deal with the weather. You have to deal with, you know, diseases and insects and animals. I mean, there's all these things you have to deal with and inside your home is a controlled environment. I guess the issue is can you control that environment and actually make it what these plants need. So that kind of brings me to artificial light. So if you're willing to introduce some degree of artificial light, do your answers to these questions start to change, the the possibilities tend to open up a little bit more with actually potentially being able to get fruit inside your house,
Emma E
it's kind of a tough question, to be honest with you, I would say potentially, but it's not going to be easy. In order to get a plant to flower into fruit, you need to make sure it's getting the right wavelengths of light, as well as the right intensity of light. And also temperature comes into the equation as well. So this would be a really technical project, if you're trying to grow, let's say, strawberries inside your home, or grapes inside your home year round, probably not something that most people are gonna want. Because it's not gonna look very attractive, you know, this isn't gonna be a real idyllic looking planter in your home, this is gonna look like a full blown production setup. And it might be hard to actually find exactly what you need in terms of lighting and temperature, you'd be having to look at production scale, research documents, to try to figure out what's going to work inside your home. And when you get down to it when you're investing all this time into infrastructure, basically. So if you're, if you're setting up a whole bunch of lights to try to be producing fruits, saving money is definitely out of the equation, right? The economy of scale, if you're just trying to grow half a dozen strawberries, or let's say, one Kiwi plant, or you know a nectarine are something, it's really going to be an expensive hobby, and you're probably not going to be rewarded with a whole bunch of fruit. I think a better approach is to grow fruits that can be brought indoors over the winter, and then brought outdoors in the summer, to a more ideal growing environment where they can really thrive.
Nate B
Right? Okay, so, and we are going to talk about that in detail. But essentially, you're not messing with all of these things, trying to give them ideal conditions in the house over winter, you're really just trying to get them from fall to spring, you know, alive, it reasonably healthy, healthy enough that they can perk right back up once you bring them outside. But if you're really gung ho, again, you're wanting to grow in a controlled environment. I mean, would a greenhouse you even mentioned a heated greenhouse be the way to grow? If I mean, you know, money, those types of things are, you know, no obstacle.
Emma E
yes, money is no obstacle than having a greenhouse is definitely the way to go, you are going to want it to be heated. Depending on the fruit you're growing, it may need to be different temperatures. So say you're trying to grow bananas, it's gonna need to be pretty warm, versus trying to grow more temperate crop like grapes, where you're probably just going to try to be keeping it above freezing in the winter, and then having them produced during the growing season. Clearly, this is not a not a cheap, you know, not a cheap project at all, but can be really fun. It's something that people used to do. You know, back in the Victorian days, wealthy people used to have their own private greenhouses where they grew their own oranges and peaches or or ferns are other house plants. But it's not something you see so much anymore. I think just because the expense is so much,
Nate B
I mean, not only would the expense be a lot, but back then you might not have been able to really get top quality tropical fruits in the way that you are now where they're potentially overnighted, you know, to a grocery store near you the back then, like if you wanted to have a fresh orange, you might have had to grow it yourself. So, you know, things have changed. But look, a lot of people want to do this. And the reason is not to save money, right there there. It's genuinely extremely satisfying to potentially get fruit, especially tropical fruit or Mediterranean for things like that. In this way, it seems like a really big accomplishment. And we do in this episode, want to give you kind of the tips and tricks to be able to do that. But we don't want to mislead you either. So I you know, I mentioned some varieties when I was giving that initial list, because if you do some internet searching, if you're going to very quickly see that these blogs are really talking about how if you choose the right varieties, you're all set where it's, you know, it's all about, you know, getting that dwarf variety, which, you know, I think is right. You know, but they also talk about some varieties being more amenable to growing in containers. So how important is variety choice when growing in this way? You know, is it the most important thing, pretty important, not so important?
Emma E
Well, I'd say look at species first and have realistic expectations. So in general, citrus tends to be a pretty good indoor plant, you do want to choose a variety that's going to be on the smaller side. So sometimes that means Dorf varieties that have been bred really for the intent of growing them in containers, or it just growing hybrids or species that that don't get all that big. You know, for example, lemons, if you're growing a straight species lemon, it can grow 20 plus feet tall and 15 plus feet wide, which, you know, obviously is far too big for the average home. And if you're trying to grow a full size tree like that, typically pruning isn't really the answer, that tree is just going to be fighting you as long as you have it because it wants to grow to a certain size and maybe doesn't want to stay to four or five foot specimen that's gonna fit nicely in your, you know, south facing window. There are definitely a few other fruit fruit varieties or other fruit species that I think are worth trying. If you're a home grower and you're really enthusiastic about it. figs can definitely be grown in containers, the climate in New Hampshire is not warm enough, there are rather our winters are still too cold for figs to be able to survive outside. But if you have them potted, and you can bring them either into an unheated greenhouse, maybe into a garage, you can you can keep them going. So you're not going to have them inside growing actively all year round, but you could still you know, have have figs that you're getting production from year to year. passion flower, which of course produces passion fruit is another one that that does, you know pretty well in containers that can go inside and outside. And I wouldn't shy away from possibly trying to grow pomegranate or olives too.
Nate B
Okay, so we're starting to get into the realm of inspiring enticing this this started off a little bit on the downer side. But okay, you're, you're giving us some ideas, you're throwing us a bone here saying that there are some of these fruits that you can grow. I'm just curious, because I have seen this particular tip quite a bit saying, Well, sure, this particular variety could grow to be 20 plus feet tall, but all you have to do is keep it in a small pot. Is that right?
Emma E
Hmm. So not quite. Close, I guess. So to a certain extent you can control plant size, by by pruning the roots. Actually, if you're if you're looking at dwarfing plants, that it's most extreme, you're talking about bonsai, where you're you're very actively pruning roots and stems and branches to keep the plant small. So there's a possibility there. More often than not, though a plant is going to continue to grow a little bit by little bit. And it is going to be necessary to put it into a bigger pot at some point like it's, you're not going to be able to dwarf it entirely just by keeping it in a small container. So it is more important to be growing something that is going to stay smaller, let's say Meyer lemon, which doesn't typically exceed eight to 10 feet. So that's going to be more appropriate. Having plants in containers tends to have a bit of a dwarfing effect, you know, in itself, versus having that plant growing in its ideal location outside. So if a plant is drying out really, really quickly. If it's looking like there's, there's signs of stress, like like the edges of leaves starting to curl and dry, if it's really not flowering or producing at all, is a chance that that pot is too small. So that only does so much.
Nate B
Okay, so there's something to that idea, but it's certainly more complicated and definitely not the silver bullet that some people may say it is. another pretty popular idea. There are a lot of garden hack videos out there. You know that kind of go viral talking about how you can turn various pieces of grocery store fruit into productive fruit trees and these videos make it seem like that's happening very quickly. By the way, you know, a really classic example is the avocado seed toothpick water sprouting trick that I've seen many times, but certainly, we hear from people frequently, who take seeds from, you know, a lemon or something like that and really baby them for years trying to get a productive tree. So I guess my question is, what about starting fruits from seed seems on the surface, like a real cost saver because getting these established fruits from your local nursery is not cheap.
Emma E
Yeah, I mean, I don't see any problem with with starting a fruit tree from seed, just if you're curious if you want to experiment and see if you can do it. That avocado seed sprouting experiment that you talked about earlier with the toothpicks and the water, that can be really, really fun. And that avocado seed is so big. And that resulting germinating embryo is you know, good size too. So it's, it's kind of a cool thing to do with kids. Same thing with seeds, you might get out of an orange or lemon, I mean, there's definitely nothing wrong with going ahead and planting that seed. The thing is your your expectations need to be realistic, though. So indoor plants. So in in I should say, like an indoor avocado plant isn't very likely to ever fruit, more of what you're going to be growing is just an ornamental tree. And avocados do have nice looking foliage. But it's just unlikely that that plant is going to be getting optimal growing conditions, it needs to actually flower and fruit. Frankly, just our climate isn't quite right for that either. I'm not sure how successful you would be growing an avocado tree, even in a greenhouse, they also get very, very large. So usually in practice, they're actually grafted, and there are specific varieties that are being grown. So if you started from seed, you're probably more likely getting what would be a straight species avocado plant, which gosh, you know, could be over 40 feet tall. By the time it's, it's done growing. So don't expect fruit, if you just, you know, are interested in seeing what an avocado plant looks like, you know, grow out of sapling. And you know, just enjoy looking at that. And, you know, at watching it grow, but don't expect a lot from it. Now the same thing goes for citrus really growing those from seed. A lot of the grocery store citrus is from either hybrid or named varieties. So that what that means is that the plants that grow from save seed, usually won't resemble the parent plant, or they won't come true to seed. This is true for say Meyer lemons, which are very popular, these are hybrid plants. So you're not going to get if you know anything about genetics at all, you know, with a hybrid, you don't end up with a plant that comes true to seed her the seed from that plant. So what I've tried this and I did try this with an orange years ago, what I ended up with was a very large, thorny tree that just produced these really small, bitter oranges that were packed with seeds. They were really beautiful. And it was neat to have this tree that was started from a seed. But it wasn't like I'd actually produced a really good quality plant that was that was producing fruit that I actually wanted to eat.
Nate B
I guess it really gives you an appreciation for plant breeders and, you know, the whole process of actually getting one of those maybe started citrus plants to a nursery where it's the right variety to healthy plant. A lot goes into it. So I mean, I agree it's it's a fun idea to experiment with. But there is some scientific reasons why, you know, the the the fruit might not be what you think it would be kind of similar topic. Again, I was searching around looking at blogs, YouTube videos, all that stuff. And there's quite a bit about stratifying stone fruit pits, like a peach is really the key to turning that pit into a fruit tree. I was really shocked how many articles there were about this. Yeah, talking about how if you stratify correctly, you're gonna have a productive bearing peach tree in just a few years. So is I know this is a very similar question really, to the last one, but is that for real? What might you expect?
Emma E
I would say that again, that could be a fun experiment. But I wouldn't expect the resulting tree to actually produce the same quality fruit as the original. The big reason for that is that most of our stone fruits anyways, so let's say peaches, nectarines, plums, what have you, these plants are not propagated from seed. So the plant that you would actually buy from a nursery was not grown from a seed, it was most likely grafted onto a rootstock. So that means a branch of the variety that you want was then attached to the root system of another plant, and grown out so that you actually have a tree that is identical to the variety that you want to grow. This is true across you know, many types of fruit trees. Also in an apple, so you might be familiar with this, this grafting of varieties. when peaches, or or any of the other stone fruits are actually propagated from seed, that is to produce those root stocks that are used for grafting. So basically just that that bottom root section that that upper Scion branch is going to be attached to. So you know, it's typically you know, that that original seed started plant is not really going to be all that great. If you're just doing this as a hobby, I don't see any problem with trying to grow a tree from a seed, just be aware that it is going to take years to see a fruit, I wouldn't be surprised if it took four or more years for that plant to flower and fruit. And then there's no guarantee that that fruit is actually going to be worthwhile. I mean, like you said, there's an incredible amount of work and research and study that goes into actually producing a lot of these varieties, he'll but some of them happen, just as happy accidents to know certainly some of the the varieties that we have were, you know, found accidentally or they've been around for a long time, this definitely goes for heirloom varieties for apples, you know, could have been something that was just discovered. So that that might happen for you, too, if you're trying to grow things from seed, but I would keep your expectations low.
All right, well, it's time for my favorite segment, it's time for the featured plant. This time, I want to tell you a bit about blue passion flower, or Passiflora caerulea. This is a plant that I grow. I don't grow so much for the fruit. But it does have the potential to fruit. I like it because it has incredibly unusual flowers. So if you're not familiar, what blue passion flower looks like, go ahead and give that a Google I think you're going to be blown away by how beautiful that flower is. So blue passion flower is a vine species that's native to South America to zone seven. So this is not a plant that's going to survive in New Hampshire, if you were to plant it in the ground, at least not over the winter. But it can do really well when it's grown in containers. And that's actually how I grow my particular passion flower. I've had it for the last four years. And I bring it outside and its container in the summer, bring it back in for the winter. To be To be honest, mine grew a lot this past year, I got it up to 12 feet, and it produced a lot of flowers. So like I mentioned before, in New Hampshire, this blue passion flower really isn't going to survive outdoors. But it can be overwintered indoors pretty easily. So if you have an unheated greenhouse, that's perfect. The plant can be in there in an area where it's not going to get below freezing and it'll go semi dormant, which means it'll lose its leaves. But they'll still be some green to the stems and it will come right back as soon as we get warm weather. You can also grow it inside in the warm part of your home, but it doesn't need high humidity and a lot of light. Either way, you definitely want to keep the potting mix on the drier side through the winter because it is susceptible to root rot. And you want to be careful with your pruning. So passion flower blooms on new growth. So it also grows a lot. It's a vine that's quite vigorous. So in the fall, you can cut it back. I cut mine basically to the base, leaving just a little bit of green foliage to help it recover. And that's about it. I leave it over the winter like that in the spring it starts sprouting again, if you want to bring your plant inside and are hoping it will look a little decorative. Then you can wait and cut it back until the spring but it is important to do that just because these are so vigorous. When you do have your passion flower and a container and you have it displayed on a trellis or something similar outdoors, I have found that you don't want to train it too much, the branches are going to hang loose and droop a bit on their own. And those ones that do are going to be more inclined to flower and fruit. This plant also does okay in small plots, but it does like root space can do pretty well in a bigger container as well. So I tend to pop mine up every year repotted rather into a slightly bigger container. And it does really, really well. I haven't gotten fruit on my own blue passion flower. But you know, who knows, maybe you'll be able to, it's just a really cool, really, really cool vine. Those flowers are absolutely incredible. It's it's really easy to care for does really well outdoors in the summer in New Hampshire, and I've had great luck keeping it indoors. So I think blue passion flower is worthy of your efforts, you know, go ahead and pick one up and start growing it today.
Nate B
So when you pick up a blue passion flower, are you planting something from seed, or is that you know, maybe something that was started from a cutting?
Emma E
Ooh, either way. So I have in catalogs seen passion flower seeds before. Because blue passion flower is a straight species plant. It's it's not a cultivar or variety, it can be grown from seed and it will come true to seed it will, it will grow into a blue passion flower. The one I have though, is actually from a cutting from a friend. So if you know anyone who has one of these, they're the they're quite easy to root just by either putting a sticking a cutting in water or using a bit of rooting hormone and sticking it in a container full of potting mix.
Nate B
While everyone listening knows at least one person,
Emma E
that's true.
Nate B
So we're looking at probably if we want a return sooner rather than later buying potted plants. And that means you know, as you're bringing it home, you're probably going to be transplanting it into a larger and more attractive container. You know, so it can be on display at your home. So any tips on choosing a container. And doesn't matter what time of year, by the way, you might actually bring one of these potted fruits home.
Emma E
Well, it's easiest on the plant, if you bring it home, when the weather's a bit nicer when the weather's a bit warmer. That's probably the number one thing I'd be concerned about taking a plant out of a nice warm greenhouse, bringing it into your freezing cold car and then trying to get in into your home without damage. So, you know, if you're feeling inspired and the you know, fall spring summer, that'd be great. I know for me, I tend to get most excited about buying plants in the winter months though. So I tend to try to go out and shopping on those milder days when it's above freezing when I can hopefully get that plant to my car fairly safely. I have seen a number of indoor fruit trees, particularly citrus at garden centers in New Hampshire. There are also a lot of specialty nurseries, you can order them from, you know, kind of depends on exactly what you're looking for where you're going to find it. But you know back to what you were asking about with containers. Definitely choosing the right container is really important here for size. You know, if you buy a plant and you're pretty certain it needs to be repotted right away. Signs being that it dries out really, really quickly, perhaps roots are coming out of the bottom, it tips over really easily, then it's time to transplant right away. And you're going to want to get a container that is going to be probably no more than, let's say an inch or so in diameter wider than the container that you currently have. So when you report you don't want the existing routes to really be any further than an inch, maybe an inch and a half from the sidewalls of that pot. So it's gonna vary quite a bit, go ahead and measure the existing pot, make sure that you're getting something that's just slightly bigger. As for material, I tend to like heavier terracotta pots, just those, you know plain unglazed terracotta pots the best. And that's because the weight of these plots seem to make them less likely to tip over. They can definitely be a big issue once we're talking about growing trees so a larger citrus for example, and some of those are covered with thorns. Secretly don't want it to tip over. Plastic can work too, but it's not as stable. And one other thing I don't like about it is that it's slower to dry out, which can lead to root rot in the bottom of that pot. This is especially true for citrus, which likes a drier root zone, I usually don't use the glazed ceramic pots for the same reason, they look really nice, but I don't use those for any sort of tree fruit indoors. Having that that porosity of the unglazed terracotta is really ideal. And then, as always, whatever container you choose needs to have drainage holes, and I really can't stress this enough, there needs to be a way for excess water to get out of that pot. So if there isn't at least one large hole in the bottom of that pot, it's not something that should be getting used for really any sort of house plant unless you're growing things that are adapted to growing in a swamp environment. Really any of the trees or houseplants are going to need that. And of course, if you have a large citrus in a terracotta pot, that can get really heavy. So what I like to do is to place those plants on wheeled dollies, you know, right from the get go maybe even right as I'm transplanting get that pot set up on the dolly. So it's it's easy to roll outside for the summer and to roll back into the house come winter.
Nate B
That's a really good back saving tip right there. Sounds like it comes a little bit from experience potentially. So when you're bringing home your fruit tree, you're bringing home your container, you better also be grabbing the right potting mix and you are going to need a little bit of supplemental potting mix if you're upgrading the size of that pie and maybe for future years as well. Should you use anything special on the bottom for drainage seemed quite a bit of advice that's kind of all over the place on that subject. Should you actually be mixing in any kind of granular fertilizer from the get go as you do that transplanting? And what potting mix should you go with? What ingredients and ratios should you be looking for?
Emma E
All right, I'll start with the last thing there the potting mix, I have found that really a good quality just standard peat based potting mix works really well as as at least a base for all of the plants we're talking about today. So if I was growing, let's say fig, passion fruit, maybe an avocado that I started from a seed, I would just be growing those in just that straight standard potting mix with no additions. However, other plants Well again, the citrus likes the soil to be really really well drained or at least drain that water out quickly. So sometimes, you know you can you can fix up your potting mix, or rather make it perfect for a plant by adding a few other materials. So for citrus, that might mean adding some sand or or some other material like that, that's going to increase the porosity. Or you can go ahead and buy a potting mix that was specifically formulated for the plant you're growing. So for example, you can buy potting mix that is specifically for cactus and citrus and it'll say that right on the label. And that really takes all the guesswork out of it. Of course, that tends to be a bit more expensive. So if you're just growing one plant, that might make sense, but if you're a real citrus enthusiast, you'll probably want to work on making your own mix. As for drainage at the bottom of the pots, I don't think you really need to put any stones or sand or anything like that at the bottom of the pot. All I see that doing is potentially making the pot heavier or blocking up that bottom drainage hole and making it harder for water to get out. Now, I don't know that that's necessarily going to happen, but I see it as being unnecessary. If anything, what I would do is use just a piece of broken crockery, so a piece of a broken terracotta pot that you can put over that drainage hole, kind of as a cup over it so that you're keeping some of that potting mix from draining out of the bottom drainage hole but still allowing water to get out beneath. So you want to make sure that that broken shard isn't lying completely flat across that hole that there's there's some sort of gap where the water can get out. You know when in doubt I'd say skip this step entirely. Just fill up your container with your potting mix. Don't put anything at the bottom to cover up those drainage holes. The probably the only time that I would ever advise putting anything at the bottom of a pot like stones or anything like that is if you are desperate to use a container Or that doesn't have a drainage hole. But then again, I would probably opt for just leaving a plant in a plastic container inside of that, instead of actually putting your plant in there, it's just so important to fill out that excess water to drain away. As for fertilizer, it's gonna depend a bit on what you're growing. With some plants, it can be helpful to add some compost into that potting mix at the start. So let's say your fig or your passion flower, that could be nice. But more often what what I do and what I would recommend is adding a slow release pelletized fertilizer into that mix as you plant so that that fertilizer is going to be fully dispersed throughout that potting mix, and is going to be available right around the root zone of the plant. If you forget this step, if you don't have that fertilizer on hand, you can also use slow release fertilizers as a top dressing and your containerized plants as well.
Nate B
Okay, so it's really good to hear that it depends on the fruit, that's really helpful. There's no catch all advice that applies universally, really depends. Citrus is going to be treated a little bit differently in this way, and some other ways. But my thinking is that for this next question, you're probably going to be generally treating plants mostly the same, at least in terms of the amount of light they need. You have your fruit, it's in its new container, and it's perfect potting mix, it's on its wheeled dolly. And you're deciding where it's going to go. Hopefully you kind of knew where it was going to go before you went and bought it but different story. So are you looking for a spot that stays a bit warmer? Perhaps somewhere you wouldn't find the site of suspended grow lights? So maybe not your bedroom? Do these fruits tend to like a more humid environment or a drier environment? Maybe that's one place where it depends.
Emma E
Yeah, I guess we have to come back to really knowing your plant. And what it likes. I mean, this is this is true across the board, whether we're talking house plants, whether we're talking perennials or fruits, you need to know exactly what that plant needs to grow. So in general, a south facing window in your home is going to be ideal for anything that flowers or hopefully fruits, you need highlight. And it also needs to be warmer. So if we're talking citrus, you're going to want that really bright sunny place inside the house, where the temperature is probably at minimum gonna stay above 60 degrees, I'd say above 65 is going to be even better. And where it drops down maybe five to 10 degrees at night. I think for most of us that that's, you know, that's pretty standard for inside the home in the winter months. If you're growing something, let's say like that, that Faker, the passion flower. These are plants that do prefer higher humidity. But they're also going to want to go dormant over the winter time. So you can potentially at least with the the passion flower, you can potentially keep this alive all winter long, I should say you should be able to keep some green leaves on it all winter long for decorative aspects and it might bloom a bit. But you are going to want cooler temperatures, because this is a plant that's used to a bit cooler weather. Same with a fig it's used to, you know, a very mild winter. You know being you know, zone seven plants, at least, you know used to have more of a mild winter, so keep it in a cooler spot. Again, with some light humidity that would be ideal, at least with the fig until it loses its leaves. And then you're just going to be getting prepared to move them outside in the summer. Because having at being actually exposed to outdoor conditions where it's best where you're getting plenty of light, hopefully some some nice natural rainfall. So you don't have to deal with chlorination from city water, that's really going to be the best thing for any of these fruit plants that you're trying to grow indoors.
Nate B
So one other really important consideration is watering. So you already mentioned it in the discussion about the potting mix, where your citruses are going to prefer a drier root zone. But there's more to watering than just that. How do you think about these different fruits and their watering considerations? a really common question that we hear is what type of water to use. Do you need to be using distilled water rainwater? Can you just be using regular old city tap water? What advice do you have around water?
Emma E
rainwater would definitely be ideal for all of these plants but just general city water is gonna be fun I don't expect you would really have any any sort of toxicity symptoms happening from the presence of chlorine or or fluorine in the water, which, of course is often what you get in a from a municipal water supply. I think more important than you know, the actual water source itself is making sure that the plant really does need water, and that you're being really careful and not watering on a schedule, just watering when the plant needs it. So across the board, these fruits that are grown indoors, the winter months, should really only be watered, once that potting mix or potting soil is feeling dry. So this means actually feeling the soil with your fingers down to a depth of one to two inches to make sure that it is indeed dry. And then when you do go to water watering thoroughly so that a little bit starts to trickle out of the bottom drainage hole, hopefully into a saucer that you've placed beneath it. If it's taking a really really long time for a plant to dry out, let's say you you water it, you know, maybe two weeks later the soil is still soggy. That's usually a sign that either the the drainage hole is blocked up, or the containers too big. So if you've over potted your plant, if you put it into a container that's too large, it might stay wet for too long. So just something to keep in mind. And of course, if you are using a saucer beneath that plant, make sure that you're emptying it right away. Because having that plant sit in water, not allowing oxygen to come in through that that bottom drainage hole no pore space, then you're going to run into issues with root rot potentially.
Nate B
Some people wear a suit to work. Others wear blue jeans, but dressing for the job takes on a whole new meaning for Rachel Maccini who is always ready to follow label instructions and demonstrate safe and legal spraying procedure and full gear at detail. Now for Rachel's Integrated Pest Management featured tip.
Rachel Maccini
If you're examining your plants, and you notice signs of slow growth, yellowing or discolored leaves or even premature leaf drop or anything out of the ordinary, you may have an issue that needs attention. The second step in observation is proper identification. Make sure you identify the pests or disease correctly because this will help you choose effective management and control options. Direct identification enables you to manage the real source of the problem and avoid nearly treating the symptoms. During your plant inspection. If you see small hard dark bumps or a sticky substance on your plants, this could indicate a scale problem. Scale is a common pest we see on indoor fruit trees scale in six feet by sucking sap from plants through piercing sucking mouthparts. While feeding, scale insects excrete a sweet sticky substance called honeydew. These insects can be difficult to control with traditional contact insecticides, because the waxy or cotony covering serves a protective barrier. However, a pest management program that incorporates different control measures will provide satisfactory control. So remember, scouting and monitoring plants often carefully and systematically with the goal of spotting problems early is essential for making pest management decisions and will save time and money in the long run.
Nate B
Okay, so as long as you can physically move these fruits, right, you've got them on their dolly, or, you know, some other hack or solution. I would think moving them outside over the summer would have some advantages but also potentially some disadvantages as far as pest diseases, inclement weather, nuisance wildlife, etc. So I know that you advise moving your fruits outside over the summer. But what are some ways that you can avoid or manage some of these potential challenges?
Emma E
Well, first off, you know, despite all those challenges, I do think it's worth still bringing your plants outside for the summer. Like I said before, those outdoor conditions are much better for growing and I think you'll find that those plants don't put on too much growth until they're moved outside for the summer. In terms of you know, some issues you might run into. I found that aphids can sometimes be problematic. The some of the other insects that I think tend to be more of an issue on citrus and other fruit trees don't live outside in New Hampshire. So this insects that bothers citrus aren't going to be found wild in New Hampshire. Same with mealy bugs, if you're familiar with those, those have either come with the plant when you purchased it or migrated onto your fruit plant from some other plant that you brought into your home. There's there's also potential to have some issues with fungal diseases, I think of, you know, powdery mildew probably being the most likely. And there can definitely be issues with moving plants between different environments. So from from indoors to outdoors to indoors, plants could definitely show some symptoms of stress when you're doing that, unless you're being very careful with, with how you're hardening things off.
Nate B
So there's a few other pests and diseases that come to mind for me, and I'm curious what recommendations you might have, you know, the two diseases are going to be root rot and powdery mildew. How can you prevent or manage those potentially, you know, with that outdoor indoor transition?
Emma E
okay, so for root rot, that's going to be an issue if the potting mix is staying wet for too long, or if you don't have proper drainage in the pot. So those are things to be paying attention to. One thing that can happen if you haven't transplanted your plant in a while if it's been in the same pot, sometimes that potting mix can break down to the point that it actually plugs up that bottom drainage hole. So reporting every once in a while is important there. With powdery mildew tends to be an issue when it's it's very hot and humid, but you're not getting a whole lot of precipitation or rainfall on the leaves. The leaves actually need to be dry for powdery mildew to germinate. So that's that's different from a lot of other fungal diseases, right, where you actually need moisture on the leaves. So that can sometimes be a problem in the summertime. And I would just try to manage it early on. So either pluck off leaves that show symptoms right away or or possibly use a fungicide. If it seems to be getting out of hand.
Nate B
And quick aside on root rot. What is that going to actually look like on your plant? How might you be aware that that is starting to become an issue?
Emma E
Well, one of the first things I think you'll notice that your plant looks like it's wilting, despite the fact that there's plenty of moisture in that container. So that's the first thing. Another thing is if your plant starts to feel like it's very loose in the pot, and it didn't before, you know if it was very firmly rooted, and all of a sudden, you can move that stem around. Now that's a sign that there's been some sort of root damage, maybe decay, that's that's caused that plant to come loose. And I've seen that happen on on trees that have been in the same pot for years and years and years. But as long as you're reporting every few years or so it's not going to be a problem.
Nate B
Okay, and I understand our featured question this week is on one natural product that could be used for combating several of these issues. What do you have for us this week, Emma?
Emma E
you're absolutely right. So this week, I want to answer whether neem oil should be used on plants and what it should be used for. So neem is actually a naturally occurring pesticide that comes from the seeds of the neem tree. Which, if you were to find that in the wild, you'd be in India, Nepal, Pakistan, Bangladesh. Neem products are really popular because they're not, you know, as toxic as some of the other options, you know, as long as you're using the right one. So name products have basically one of two ingredients. One is azadirachtin, which is a substance that actually kills and repels insects. After the azadirachtin is extracted from the neem oil though the remaining material is called clarified hydrophobic neem oil. And this is what you're going to find on garden center shelves, neem oil is it's really common and you'll probably find it anywhere where plants are sold. So, neem works really well against certain insects. It's not a poison. So how it kills them is actually by suffocation. So when that oil covers their bodies, it blocks their breathing openings. So in order for it to work, you actually need to get a nice coating over the entire insect itself. That means spraying both the upper and lower surfaces of leaves to find all the insects where they're located. It also works better on immature insects than adults. Typically on product labels, you'll see it recommended for things like aphids, caterpillars, lace bugs, leaf hoppers, leaf miners, maybe mealy bugs. how well it works on each of those is is varies a bit like, again, depending on the lifecycle of that insect. But one of the things to note is that it can harm beneficial insects too. So if you are having a pest issue number one, make sure your insect is listed on the product label. And make sure you don't have any beneficial caterpillars or any other insect hanging out on your plant. Neem can also be used to prevent some fungal diseases. So it won't cure a plant. But it can help limit the spread of disease to healthy tissue. So basically, if you start to see something, see something like powdery mildew, and you apply the name to the remaining healthy leaves, it'll help keep those from becoming infected. One thing I'll note is that you know, name should really only be used when you actually need it. It can absolutely damage plants by burning their foliage. And it can have harmful effects on the human body too, if it's misapplied. So remember, this goes for any pesticide, but diagnose the issue correctly. And then try non chemical control methods before you use me. But neem is absolutely a good tool to have in your toolbox.
Nate B
Okay, going back to the solution, or one of the solutions to you know, preventing root rot, as well as just good ongoing maintenance, is repotting. So you mentioned how, you know over time potting mix can break down and plug at the bottom. So that's one potential issue. So I'm curious how often do you recommend a full repot?
Emma E
I'd say it's probably only necessary to really do this full repot every two to four years or so I certainly don't think it's going to be necessary for you to be moving, say your citrus plant or your passion flower into a new pot every single year. But it is over time. So these plants are going to gradually get bigger and bigger and bigger. And they are going to need bigger pots. Like I said, if you are trying to keep the plant in the same pot, what you can do is actually prune the roots a little bit. So take it out of the pot, remove maybe the outer inch to two inches of root growth, and then report it in the same container it came out of with some fresh potting mix. Now how quickly you need to do this is really going to depend on how quickly the plant is growing and probably to a certain extent how much you're fertilizing. So I can't say that there's any real schedule here. But I'd say probably at the most, you probably want to leave something in the same pot for four to five years. And then you really want to want to take it out of the pot, see what's going on with the root system, possibly put it into a bigger pot or prune those roots.
Nate B
Okay, and so you mentioned fertilizing. So really how often should you be fertilizing? What should you be looking for and the context here is that you did recommend some kind of slow release granular fertilizer at the outset. You know, when I think fertilizer, I do have concerns about you know, salts and things like that potentially building up in the potting mix as well. So this does relate, like you said, back to repotting and the potting mix
Emma E
well for things that are grown in pots in in an artificial you know, soilless potting mix that we recommend you use, you should be using a complete fertilizer. So that's something that includes the main macronutrients, so nitrogen, phosphorus, potassium, as well as some micronutrients. If you're, you know, just using something like a organic fertilizer, let's say you may not be getting all the nutrients you need, and they may not all be available to that plant because you need a soil microbial community to actually make those available. So I typically opt for some sort of water soluble granule that I can I can water into the soil with my plant. salts can be an issue like you mentioned, Nate. So what you do want to do periodically is leech the pot so that means putting in a large amount of fresh water, so water is running out the bottom of that pot out of the drainage hole. And that what that's doing is basically flushing excess salts and fertilizers from that pot so you're starting over with a clean slate. One One thing that you can look for to kind of take the guesswork out of it is a fertilizer. That is specifically formulated for what you're growing. So say a citrus fertilizer now that those exists, but you don't necessarily need that.
Nate B
Do you see advantages of going I mean, we know it's a synthetic complete fertilizer, but granular versus liquid?
Emma E
not particularly, I think most of the fertilizers that that I use are a granular dry fertilizer that you mix up with water, I think those are a bit more common. But a liquid fertilizer would be fine as well, you know, just make sure that you're reading all the instructions on the label, and not over applying.
Nate B
could you potentially use a granular fertilizer that you're just putting on the top or maybe very lightly mixing it into the top of the potting mix, or you would really rather use something water soluble?
Emma E
so you can do both. So you can have more of a slower release encapsulated fertilizer that you're putting on the surface of that soil, that's totally fine. What you might find, though, is that during the growing season, you need a bit faster boost than that, let's say you're growing something like that, that fig gourd or that passion flower that you want to put on a whole bunch of growth, you really want to stimulate that growth, then I bet be mixing in that that quick release water soluble fertilizer, you know, just just for a shot to get it going.
Nate B
Well, I'm really glad you brought up the nutrient deficiencies can that can occur with organic fertilizers, really, because we've actually seen that where people send us pictures, and it shows a nutrient stressed plant. And so the question is, okay, are you fertilizing? And they say, Oh, yes, you know, every two, four weeks, something like that, you know, right on schedule. But turns out, they're using a fertilizer that the plant is just not able to access. So it's really important you choose something that is, you know, complete, and that the plant will really be able to use. You've talked about pruning in a couple contexts in this episode. you talked about how pruning is not a solution to keep plants that want to be really tall at a manageable size. You've also talked about root root pruning as an option. But what about just plain old pruning? You know, you have the right variety, you know, that's not going to get too big naturally, when it comes to the fruits that were growing outside. In our home orchards, pruning is a really important part of your annual routine. What role do you think it plays with potted fruits that you're bringing inside and out?
Emma E
Pruning is definitely still going to be important. From a plant health perspective, as well as from an ornamental ornamental perspective, the a lot of the principles are still going to be the same. Do you want to remove anything that's that's dead, diseased or damaged, you also want to remove branches that are that are crossing or rubbing, or, or drooping down or growing straight up in the air. So the the concepts are the same. Timing doesn't need to be quite as precise, though. So when we're talking about, again, citrus, let's say that pruning can really happen anytime before active growth starts. So I'd say from the fall to spring or so, what I tend to like to do is prune lightly in the fall, just enough to get the plant indoors to make it fit the space that I have for it to make sure that any wayward branches aren't in the way. And then I do a heavier pruning and late winter to remove those structural defects that I mentioned, like the crossing or rubbing branches. And you just need to keep in mind too, that pruning is going to impact flowering and fruiting. So if you do want to still get plenty of flowers and fruits, don't go too crazy.
Nate B
So does pruning play a role both in promoting flowering and fruiting but also potentially hindering it?
Emma E
Yeah, I guess again, it kind of depends on on what it is. So there's potential that you might be removing actually growth that would have produced a flower bud and then a fruit depending on what it is. Or if I'll go back the passion flower again, if you're trying to grow a fruit like that the pruning is actually going to stimulate potentially more flowering and in turn fruiting because those flowers occur on new growth. Versus let's say the the citrus, which is going to be forming those flower buds on a bit older growth.
Nate B
Okay, what's the difference between how you're caring for fruits when they're outside and actively growing, versus indoors over winter? Are these fruits tending to actually go dormant? Are they growing just a little bit? Are they still growing quite a bit if you keep fertilizing and, you know, give them light and what's your recommended approach to winter care specifically?
Emma E
Winter care, I'd say is not that different from how you're going to keep other house plants, you are going to want to basically slow down on the fertilizing or stop it altogether. Because these plants either aren't going to be actively growing, or they're only going to be growing a very little bit. You don't really need any fertilizer nutrients. So you can stop that from fall through the spring. But then once the days start getting longer, and you start to notice some new growth, some new leaves developing at the ends of branches, or some new vine growth, depending on what you're growing, then it's time to start fertilizing again. Depending on what you have there, there may be more of a true dormancy versus more of just kind of stasis, if you will. So your citrus is going to have leaves on it possibly going to flower over the winter, it's not going to be putting on a whole lot of vegetative growth, but it's still alive and growing. versus something like your fig, which is probably going to lose its leaves over the winter. And it's not going to be actively growing until it gets warmer until the days start getting longer again. So in that case, you want to be really careful with the watering, you don't want that soil to completely dry out. But you also don't want it to be too wet. So with a plant that has gone dormant, you're probably only going to need to water maybe once every couple of weeks.
Nate B
one of the if not the most traumatizing experience growing, you know, a fruit tree that you have poured your heart and soul into taking care of exactly how you're supposed to is when leaves start to drop left and right seemingly out of nowhere, right? you're doing everything right, and all of a sudden, the tree is just dropping its leaves. What I mean we and we see this at Extension, pretty frequently, what would you suspect is going on when that leaf drop is occurring?
Emma E
Usually I'm thinking some sort of environmental change or shift. It often happens when plants are moved from outdoors to indoors or vice versa, although I think more from outdoors to indoors. So we're talking about a major change in in temperature in light and moisture, maybe even humidity. So that leaf drop is a sign of stress for that plant. A lot of times it doesn't end up being all that harmful for the plant, maybe annoying and upsetting for you as those leaves are falling off. But a lot of times plants are able to recover from that pretty easily. What you can do though, is try to be a little bit more gentle in that hardening process of moving things outdoors to indoors. So if you're going from indoors to outdoors, you want to make sure that you're putting your plant in a real shady location when it first goes outside and gently transitioning it into full sun over the course of a week to two weeks. When you're bringing it back indoors, you're going to want to again move that plant into a shady or location so that it can get used to lower light conditions and then bring it inside. And then don't panic if you do lose some leaves because that's pretty standard for bringing plants in for the winter.
Nate B
So if you've brought your plant in, and it starts to lose leaves, are you going to expect that the leaves are going to regrow over the course of winter? Or might you actually have to wait until spring when it goes outside for the leaves to regrow?
Emma E
probably depends a bit on what the environment is like inside your home. And also the extent of the leaf loss. If your home is is very warm, if you have bright light. If the humidity is is good, then I would expect to see some new leaves developing but probably not a whole lot. Or that growth is not going to be significant enough to make up for what was lost. But once the conditions for that plant improve and you are able to get it outside again, that's when you typically will see the growth really take off.
Nate B
Aha. Another issue that we sometimes see not as traumatizing, perhaps, but certainly frustrating, is brown tips on the leaves. This is certainly not just limited to fruit. It's an issue that we see with all kinds of foliage houseplants but what would you suspect is going on if your fruit tree starts to get brown tips?
Emma E
could be a few different things or a combination of things. First, it could be a watering issue. So if you've been letting that plant get too dry in between watering sometimes drought can lead to some brown crinkled edges on leaves could possibly be from over fertilization or a buildup of salts in the soil, so that leaching the pot with a whole bunch of fresh water is helpful. Or it could be a sign that the humidity isn't quite right. I know some of some of my house plants that like a real humid environment and aren't getting it indoors in the winter in my home, get these these brown crinkly edges, which I fully anticipate the plant will survive, it's just not gonna look the most attractive until it gets ideal growing conditions again.
Nate B
right, and those leaves this specifically the ones that are getting brown tips, they're never going to recover, right. So you might, once the plant starts to put on new growth, you might actually be cutting those leaves with brown chips off, or would you just be cutting the brown chips themselves off?
Emma E
kind of depends. Usually, for me, I'm just trying to dress up the plant as much as I can over the winter. So I might be pruning just that little brown edge off, or the brown tip off of a leaf. Once I'm seeing a whole bunch of new growth outside, if the plant doesn't abort that leaf on its own, then I might actually go in and pluck it off or clip it off just to make it look a bit nicer.
Nate B
One last issue that we see, really, really frustrating issue is when a gardener is able to actually get really good flower set, but it doesn't lead to fruit. You know, maybe they get one measly fruit or you know nothing at all, what might be going on that's preventing those flowers from turning into fruit?
Emma E
Well, it could be a pollination issue, which is probably the first thing I'm thinking of. If your fruits haven't been outside at all, or at least they bloom while they're indoors, could be an issue of not having pollinators present. So most things that have showy flowers are going to be insect pollinated. And usually that means bees, most of us also aren't going to have bees in our homes. So if there isn't, if there is not adequate pollen transfer from the male part of the flower to the female part, then you're not going to get fruit. So in some cases, you can play the part of the insect yourself either by flicking the flowers with the tip of your finger or maybe using a cotton swab to transfer pollen from one to the other. Another thing to keep in mind too, is that some fruits are self pollinating, which means pollen can come from the same flower, or the pot. Basically, a flower can pollinate itself. So the pollen within that flower can can pollinate the female part of the flower. Some plants are not. So with with some plants, you actually need two different varieties if you want to get fruit. This is really true for some of the stone fruits, let's say where you need to have to.
Nate B
that started to get pretty graphic. I'm glad you kept it appropriate for all ages there, but I wasn't quite sure where you're going after, you know, you're flicking the flower and all that stuff. But okay, good. Let's take a few steps back. We've talked really in detail about how to grow these fruits at home. But what are reasonable expectations for trying to grow these fruits, assuming you're following all this great advice that you're sharing Emma?
Emma E
I would say ultimately, don't expect a ton of fruit. You should be growing these plants for fun without the expectation that you're going to be getting some sort of big harvest that's going to satisfy all your fruit needs in your home. Indoor fruit plants I think should first and foremost be ornamental. That fruit is really just a nice side benefit. And if you're doing everything right, chances are that you are going to get a few fruits here and there. But having that plant around just because you enjoy it and you think it's beautiful and interesting, I think is the most important thing.
Nate B
Bring us home with our closing gardening tip.
Emma E
All right, so we're gonna move from indoors to outdoors. If you're somebody who has trees and shrubs on your property, you pretty much you know, assume that invariably they're going to get broken branches from Snow wind ice over the winter months. If this does happen to your plant, if you get some broken branches, what you really should do is get out there and prune them as soon as possible. This is so that you can prevent the bark that's on those branches from tearing and causing further damage. Now winter is not the ideal time to be doing a lot of pruning. But when it comes to just removing damaged parts, that's totally fine. I'll also say that it's rarely possible to actually save broken limbs on trees. And it's pretty much always better to just remove them rather than trying to tie them up. support them in some way to keep them alive. There's also no need to cover the wounds with any sort of wound pain, burlap or plastic. Just leave that injured area open to the air so that the plant can seal over the wound naturally.
Nate B
Our goal with Granite State Gardening is to explore the world of gardening and help you achieve success in your garden, whether it's indoors or outdoors, or like us both. Of course, we're sticklers for research based information here UNH Extension so you can count on us to share proven tips and solutions. We want to meet you where you're at as a gardener, so we're really going to count on your feedback. How have you enjoyed these last three episodes on Victory Gardens on growing herbs indoors and growing fruits indoors? What topics do you want us to explore with you and as the information we're sharing, if too advanced too basic, or just right for you? Email us with your questions about this episode previous episodes, and for future episodes at GSG.pod@unh.edu. As a brand new podcast we would greatly appreciate if you would share this podcast with fellow gardening enthusiasts. And if you enjoyed this episode and previous episodes, consider giving us a five star review wherever you're listening. Thanks for tuning in to Granite State gardening from UNH Extension. Until next time, keep on growing and getting bountiful fruits inside and outside your home, Granite State gardeners, we'll talk to you next time.
Granite State gardening is a production of the University of New Hampshire Cooperative Extension and equal opportunity educator and use expressed on this podcast are not necessarily those of the universities, its trustees, or its volunteers. inclusion or exclusion of commercial products in this podcast does not imply endorsement. by the University of New Hampshire, US Department of Agriculture and New Hampshire counties cooperate to provide extension programming in the Granite State. Learn more at extension.unh.edu
